br947 at FreeNet.Carleton.CA (Caterine Wheatcroft) wrote:
>Why do the shoots of pole beans grow counter-clockwise and not
>clockwise? Any information would be welcome.
The most of twining plants grow clockwise indeed,like Morning Glory(Ipomea) and
Convolvulus, but some grow counterclockwise, like Honeysuckle (Lonicera).
Be aware, however of the fact that clockwise or anticlockwise is just a
convention, Linnaeus for instance considered clockwise what the physicists
consider counterclockwise (clockwise is the commom screw).
As concerns plants the side of the earth where they grow shouldn't have
any effect on the handedness, as has no effect on snails.
But read: The handedness of the universe. Sci.American 1, 108-15 (1990).
I have however another question: what could be the exact relation between
right and left hand spiralling in plants (twining plants, circumnutation)
and right and left handedeness in mammals (like men) and other animals? If
the definition of right and left spirals is a convention no relationship
should exist, but in fact it seems to exist and the enormous prevalence of
right hand spirals in nature (DNA, proteins) should be connected with
handedness in animals.
I hope this discussion will proceed. The study of twining plants and plants
movements is exciting!
Read also: Darwin C. and F. The power of movement in plants. Appleton and
Co. 1981.
Miglia at vm.icmat.mlib.cnr.it